Air controlled fuel burner



June 5, 1945 R. c. HOPKINS AIR CONTROLLED FUEL:A BUFR Filed Jan; '1,4 1943 3 Sheets-Sheet 1 A ww @19% f bh Nw Sm mn ww o. Km o m Q Mm, ||||1 mvo. hm .w QN mmf wm 3% N l N Il f wm @N RN 1 1 l Il: rv l l x I WN um., mw NN. l mw -1 RN QN June 5, 1945 R. c. HOPKINS AIR CONTROLLED FUEL BURNER Filed Jan. '7, 1943 5 Sheets-Sheet 2 m2@ hij@ Q m Fw 0 im M June 5, 1945.'

R. C. HOPKINS AIR CONTROLLED FUEL BURNER Filed Jan. "l, 1945' 3 sheets-sheet s mwN 31u/venlo@ JZOe/ C. [YW/was w, www @M ttoump Patented June 5, 1945 U N IT'ED STATES PAT EN T 0F Filf'Ci. .2,377,497 l v AmcoNTnoLLEp FUEL'BURNER i Robert C. Hopkins, Alliance, .Ohio Application January 7, 1943,l Serial No..471,589

'z claims. (criss-99) The invention relates to fuel burners and more particularly to a-gas burner having air operated means controlled by the furnace temperature for regulatinglthe gas supply to the burner.

Burner controls such as are now in .general use are ordinarily operated by expensive apparatus which includes motors specially built and adjusted so as to produce a reciprocating vmotion whereby the controlpa'rts are moved. forward trolmeans.

An object of the invention is Ato provide aburner having a gas tube and a mixing chamber telescopically connected together with meansfor producing relative sliding movement between the gas tube and mixing chamber to simultaneously.

control Athe gas ow and air combustion at the burner nozzle.

Another object is to provide air-*operated means controlled by the furnace temperature for producing relative movement :between the gas tube and the mixing chamber.

A further object is to .provide a metal bellows, or the like, operating with the -air pressure required for combustion to regulate the flow of gas and air of combustion.

A still further object is the provision of a burner of the character referred to having a gas tube closed at the end toward the burner nozzle and provided with a series of slots adjacent-said end to permit the ow of gas, and e. mixing chamber sldably mounted -upon said gas tube and movable over said slots to regulate the'gas-fiow therefrom.

Another objectof the invention is -to provide a burner of the character just described in -which air under pressure is admitted tangentially to the mixing chamber thus setting up a spinning motion inside the mixing chamber, the gas being introduced at the center of the mixingchamber and therefore in the center of -the spinning air.

Still another object 4is to provide -a burner of this character in which a ring -is carried Aby Athe mixing chamber and arranged lto be adjusted relative to the nozzle plate to regulate the air for combustion.

A further Vobject is izo-provide a-burner of .this character in whichthe rng-isspaced from-the tip of the mixing chamber-so that -the .premixiaire of air and gas within the mixing chamberitself is completed with second-and-.third stage -air iiow throughthe .orifice-between the ring .and 'the mixing .chamber-and also between the outside of the ring -and the nozzleplate; ofI the burner.

.AA .stilL furthenobject.of-the=invention .-is to yprovide a burner-of cthischar-acterin jwhichmeans is providedfor -adi'ustingithe position of lthe gas tube rlativeto-the-nozzlefofQ-the burner.

which the-gas-ow-and air-forcombustionat the Another object is to provide such a burner xin burner nozzle acre automatically -rregulated 'and the desired proportioncan be established and maintained' between-fthegas andtairf and'atthe same time a manualiyfoperated blastfgate fcontrolsthe admission ofaintofthe burner easing.

Still another object isfthefprovisionof Ia-irurner of the-type :referred-to whiclntl'xemetal bellows'hasasuicient amountwof spring quality to operate -the mixing-chamber relative-tothe -gas 1I tube in one direction whiclrtheompressed air operatesftheI-m-ixinjg chamber-1in=.the Iopposite dimotion-against:thespng-action.

A-still further object of the=inventionis the provision of an elongated burner 'casing having a gas tube extending longitudinally therethrough, closed -at the end'towardrthe-burner nozzle and provided-With aseriesof vslots-adjacent this end, a mixing :chamber .being slidably .mounted upon the 'gas'ftube and having vtangential openings therein, -means for'admittingfanair 'blast' to the interior of the :casingg-ang .carried bythe mixing chamber and spaced-therefrom; a'metal oellows, or'cylinder fand'piston, located adj acentto the burner casing, a low "pressure compressed air line leadingtheretq-*a solenoid or motor valve in'said air line, 'a'fpyronieterfnd thermocouple controlling said-valve, Aand linkage connecting' the metal'b'llows' oripiston th the slidable mixing chamber for automatically adjusting the'same to'controlthe-ga'sf'iiow'and airfror combustion.

The above objects -together with' others which will be'apparentfrom' the drawings and following description, or 'which may be'later referred to, may' be attained by vconstructing the improved' burner-dln;- the manner illustrated in the accompanyidndrawlne, in'which- Figure 1 is a diagrammatic view showing the improved 'burner operatively `connected to a' furliac:

Fig. 2, an enlarged'top lplan view'o'rthe burner:

Fig. 3, a vertical longitudinal sectional view through the burner partly in elevation;

Fig. 4, a transverse section through the burner,

at the mixing chamber, taken as on the line 4-4,

Fig. 3;

Fig. 5, a transverse sectional view through the burner, at the nozzle plate, taken as on the line 5 5, Fig. 3; and

Fig. 6, an end elevation of the rear or outer end of the burner.

Similar numerals refer to similar parts throughout the drawings.

The burner casing, indicated generally at I0, may be substantially cylindrical and closed at its rear end by the end plate I I connected thereto as by the screws I2.

The upper side of the casing I is-provided, near the rear end thereof, with the air` inlet opening I3 for receiving an air blast from the air line I4.

If desired a blast gate may be provided to control an`d regulate the air blast entering the casing at this point. This blast gate may be in the form of a slidable plate I mounted in a housing I8 attached to the upper, side of the casing as by screws I1. v

For the purpose of operating the blast gate a rod I8 may be xed thereto, as by the bracket I9 and screws 20, and slidably located through a bore 2I in the boss 22 formed upon the housing I6, the outer end of the rod having a handle 23 connected thereto. A set screw 24 may be threaded through the boss 22 for frictional engagement with the rod I8 to hold the blast gate in adjusted position.

A gas tube 25 extends longitudinally through the central portion of the casing IU being adjustably mounted through the end blast I I as by the screw threads 26. The outer end of the gas tube is attached to a coupling 21 to which may be connected one or more gas pipes 28 leading from a suitable source of supply.

The forward end of the gas tube 25 terminates at a point spaced from the nozzle plate 29 which may be attached to the forward end of the casing I0 as by screws 38.

This end of the gas tube is closed as by an end plate or plug 3I and a series of longitudinal slots 32 is milled or otherwise formed in this end portion of the gas tube to permit gas flow therethrough.

The mixing chamber, indicated generally at 33, is provided with va plurality of tangential openings 34 so that the air blast from the interior of the casing may enter the mixing chamber tangentially setting up a spinning motion within the mixing chamber. The gas is introduced from the slots 32 in the gas tube into the central portion of the mixing chamber and thus within the center of the spinning air.`

The forward end of the mixing chamber is preferably in the form of a hollow truncated cone as indicated at 35. A ring 36, having the conical forward portion 31, is concentrically spaced around the conical end 35 of the mixing chamber, being `preferably connected thereto as by the radial webs 38.

" 'miner is provided with a sleeve 39, slidably mounted upon the gas tube 25 and so positioned relative to the inner end ofsthe gas tube that it may cut oi any part or all of the slots 32 so as to regulate the gas flow therethrough.

For the purpose of slidably moving the mixing chamber upon the gas tube a metal bellows, or cylinder and piston, is provided.

CIT.

In the drawings a metal bellows is shown indicated generally at 4|! and provided with the rod 4I connected to the lower end of a lever 42, fulcrumed at 43 upon a bracket 44 connected to, or formed upon, the end plate II. The cylinder or bellows 40 is also suspended from the burner casing as by a bracket 45 which may be attached to the casing as by screws 46.

The upper end of the lever 42 is pivotally connected as at 41 to the outer end of a rod 48, slidably located through an opening 49 in the end plate- II, and having its-other end connected to the depending lug 50 upon the sleeve 39.

For the purpose of operating the bellows, or cylinder and piston. a low pressure, compressed air line 5 I .is connected thereto and provided with a solenoid or motor operated valve 52, as shown in Figure 1.

In this figure a burner is shown connected to a furnace, a portion of which is indicated at 53. Y

A thermocouple 54 is located in the furnace and connected by wires 55 to a pyrometer 56 which may be ,ofeither' the plain or recording type.

The wires 51 and 58 lead from a. suitable source of electric energy, the wire 51 leading to the solenoid or motor valve 52 and the wire 58 leading to the-pyrometer 56, a wire 59 connecting the pyrometer and valve.

In assembling the burner the gas tube 25 is adjusted, by means of the screw threads 26 to the desired position within the burner, placing the slots 32 therein at the required distance from the nozzle plate 29.

The mixing chamber 33 is slidably mounted upon the forwardend portion of the gas tube in such position that in the full operation thereof upon the gas tube the mixing chamber will move from one end of the slots 32 to the other so that it may assume any position from fully opened to fully closed slots.

As the mixing chamber is moved forward it entirely vcloses the slots 32 and the conical portion 31 of the ring 38 contacts the conical opening 6I! in theA nozzle plate 29 cutting off air of combustion between the ring and nozzle plate but still permitting a flow of air between the conical portion 35 ofthe vmixing chamber and the ring.

As the mixing chamber is moved backward it entirely uncovers all of the slots 32, giving the maximum gas ow and moves the ring 31 a corresponding distance away from the nozzle plate thus permitting the maximum air now.

At any intermediate point the established ratio of gas and-air is thus maintained.

In the position shown in Figure 3 of the drawings the gas slots 32 are slightly more than half closed and the space between the conical portion 31 of the ring and the opening 60 of the burner plate is correspondingly reduced.

In actual use the air pressure may be anywhere from four ounces up to sixteen ounces, or even greater if desired, and the gas pressure ranges from four ounces up to the maximum air pressure.

Although a cylinder and piston may be provided for operating the sliding mixing chamber a metal bellows, such as shown at 40' in the-drawings, is preferredbeeause the bellows has suicient spring quality to cause it to assume a closed position under normal air pressure thus moving the mixing chamber to a position to fully uncover the slots 32, while when the valve 52 is opened air pressure admitted to the bellows through the pipe 5I moves the mixing chamber in the opposite direction, against the spring action of the bellows.

This construction obviates the necessity of an additional spring means which is required Where a bellows.

The pipe is connected to a suitable source of low pressure, compressed air, the pressure being of any intensity from four ounces up to the maximum available for operating the burner,

The blast gate I5 may be manually adjusted,

position by the set screw 24, to regulate the air blast admitted to the interior of the burner casing, as may be desired, and with any established setting of the blast gate the control of the burner by the mechanism above described is automatic, the flow of air and gas to the burner nozzle being proportionately increased or decreased to meet the demands of the furnace.

Through the thermocouple 56 the valve 52 is operated to increase or decrease the air pressure to the bellows operating the slidable mixing chamber to regulate the air and gas flow as required by the furnace. If desired the pable of gradual opening and closing although this is not entirely essential since the spring quality of the metal lbellows 40 will cause the ope `quantities of air and gas admitted to the burner. Although the invention is above described as stood that without any change in the construc y tion of the burner fugLoils may be atomized and very e'ciently burned therein.v

Ic a Y 1. A burner including a, casing having a nozzle at one end, means for admitting air under pressure to the casing, a gas tube located in the casing and terminating in a closed end from the nozzle, there being openings in the gas tube adjacent to said closed end, means for admitting gas to the gas tube, a mixing chamber slidably mounted upon the gas tube and positioned to slide over said openings, meansfor admitting air tangentially into the mixing chamber from the casing to produce a spinning motion of the air in the mixing chamber around the gas 50 gas tube to the mixing chamber and for regulatintroduced at the center of the mixing chamber through said openings and means for producing relative sliding movement between the mixing chamber and gas tube for regulating the gas flow from the gas tube'to the mixing chamber.

2. A burner including a casing having a, nozzle at one end, means for admitting air under pressure to the casing, a gas tube located in the casing and terminating in a closed end spaced from ,A I

the nozzle, there being openings in the gas tube adjacent to said closed end, means for admitting gas to the gas tube, a mixing chamber slidably Amounted upon the gas tube and positioned to slide over said openings, means upon the exterior of the mixing chamber cooperating with the nozzle for regulating -the air of combustion at the nozzle of the burner and means for producing relative sliding movement between the mixing chamber and gas tube for regulating the gas flow from' the gas tube to the mixing chamber and for regulating the air of combustion at the nomle.

3. A burner including a casing having a nozzle at one end, means for admitting air under pressure to the casing.- a gas tube located inthe casing cylinder and piston are usedV in place 'of the by means of the handle 23 and held in adjusted 54 and pyrometer valve 52 and its solenoid may be of a type cal o5 sure to the casing.' ages. tube locatedin the casing and-terminating in a closedl end spaced/from the;v nozzle, there being openngsin the gas ube adje-iy 'ngmovement thereof to be gradual .l 'cent to said closed end,'m ean s'foradju ting the l so as to provide for continuous regulation of the Y -o ting gasto thegastube,a niixing'jchambers dab1y`. f ",tubeiandgpositionedgto slide a gas burner and is especially adapted for burny Ying natural or producer gas it should be under-...1,-

spaced and terminating in a closed end spaced from the nozzle, there being openings in the gas tube adjacent rto said closed end, means for admitting gas to the gas tube, a mixing chamber slidably 5 mountedupon the gas tube and positioned to slide over said openings and a compressed air operated -device for' producing relative sliding movement between the mixing chamber and gas tube -for regulating the gas now from the gas tube tothe mixing chamber.

4. A burner including a casing having a nozzle at one end, means for admitting air under pressure to the casing, a manually operated blast gate for controlling the admission of air -to the casing,

.a gas tube located in the casing and terminating in a closed end spaced from the nozzle, there being openings in the gas tube adjacent to said closed "end, means for admitting gas` to the gas tube, a mixing chamber slidably mounted upon 2o the gas` tube and positioned to slide over said' openings for .regulating the gas flow from the gasv tube to the mixing` chamber.v

.5. A bomen-including a casing yhaving nozzle v at one end, means for admitting air under. presmounted upon ithe'g over'said openings"for'ifregulatingtheigasnow' A i from the lgas 'tube tothe-'mixing' chamben 6. A-burnerfincludingfrcsmghaving -a-nozzle .5 at one end, means lfor,admittinglairunder pres;`

sure to the casing,fa gas tube located in the casingii.

and terminating [aclosedgendv spaced from the nozzle,v therejbeing openingsin the gas tube adjacent to said 4closed endffmeans for admitting lo gas to the gas tube', amixing'chamber slidably the exterior thereof so that air of combustion may passA fromtthe casing between the. mixing chamber and'fring' and between the ring and nozzle, ythe mixing chamber being slidable upon the gas tube for regulating the gas flow from the ing the air of combustion at the nozzle.

i 7. A burner including a casing having a nozzle at one end, means for admitting air under pressure to the casing, algas tube located in the casing and terminating in a closed end spaced from the nozzle, there being opeinngs in the gas tube adjacent to said closed end, means for admitting gas to thef gas tube, a mixing chamber slidably mounted upony the gas tube and positioned to slide over said openings, means for admitting air tangentially into the mixing chamber from the casing to produce a spinning motion of the air in the mixing chamber around the gas introduced at the center of the mixing chamber through said openings, means'upon the exteriorv of the mixing chamber cooperating with the nozzle for regulating .the air of combustion at the nozzle of the burner amLmeans forproducing ,relative sliding movement between the mixing chamber andgas tube fr regulating -the gas iiow from the gas tube to the mixing chamber;

' ROBERT C. HOPKINS.

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